Dental caries (tooth decay) is one of the most prevalent chronic diseases in all populations worldwide. If caries progresses and severely inflames the pulp tissues inside the tooth, a root canal procedure is often performed to remove the necrotic dental tissues and seal the tooth with bio-inert materials. While this therapy has been used for many years with high success rates, the tooth repair it offers is non-biological and has limitations. The regeneration of dental tissues using a tissue engineering strategy represents a promising approach to replacing damaged dentin/pulp structures and restoring their biological functions. So far, the regeneration of the physiologic dentin/pulp complex with tubular dentin enclosing the vascular pulp has not been achieved. Without a well-organized structure, the regenerated dental tissues cannot perform normal mechanical and biological functions. In our preliminary study, we developed a unique approach to fabricating a well- organized biomimetic matrix to guide tubular structure formation from dental pulp stem cells (DPSCs). We also utilized the matrix stiffness to form a dentin-pulp complex and developed a facile method to sustain the release of vascular endothelial growth factor (VEGF) to induce angiogenesis. Therefore, in this application, we propose to regenerate the tubular vascularized pulpodentin complex. We hypothesize that 1) a bioengineered tubular pulpodentin complex can be regenerated by tailoring biomimetic nano-structured scaffolds capable of conferring suitable biophysical cues to the engineered constructs; and 2) the controlled delivery of VEGF from the biomimetic scaffold will revascularize the tubular pulpodentin construct. For this study, three specific aims are proposed. In Aim 1 we will regenerate the tubular dentin structure. We will fabricate, characterize, and optimize a biomimetic tubular gelatin matrix, as well as engineer the tubular dentin structure from DPSCs with the guidance of the tubular gelatin matrix. In Aim 2 the goal is to regenerate the tubular pulpodentin complex in a tooth slice model in vivo. Aim 3 will focus on revascularizing the tubular pulpodentin complex using a clinically- related in vivo tooth fragment model with only one opening to the blood supply while the other end is sealed. Successfully completing this work will lay the groundwork for future testing of our innovative materials in clinical trials to determine their therapeutic capacity for the regeneration of the pulpodentin.